The present invention relates to an apparatus for decontaminating a stream of compressed air or the like by removing unwanted particles, gas, or vapor from the compressed air stream using a single or multistage filter. More particularly, the present invention relates to a point of use modular filter assembly including a cartridge housing, a self-contained filter cartridge positionable in the housing, and a manifold cap attachable to the housing for conducting a compressed air stream between an air line and the filter cartridge in the housing.
Filter elements deployed in filter assemblies must be replaced periodically as the elements become occluded with contaminant material trapped therein or otherwise fail to function properly. Service persons charged with the responsibility of replacing worn filter elements often encounter difficulty or other delay in dismantling a mounted filter assembly to a point where the worn element can be removed from the assembly for replacement. Such problems can result from the complicated, cumbersome filter element-retaining and manifold cap-attachment structures used in many conventional filter assemblies. A filter assembly constructed of easily assembled and disassembled modular components would make the job of filter element replacement much easier and less time-consuming and would avoid shortcomings of conventional compressed air filter assemblies.
One object of the present invention is to provide an easily replaceable, self-contained, modular filter cartridge that is insertable into a protective housing and supportable in a fixed position therein to filter a compressed air stream admitted into the housing.
The utility of a compressed air filter assembly is enhanced by providing the maximum filtering capacity in an assembly having the smallest possible volume. Small air filter assemblies are desired because they are usable in a wide variety of applications where the space available to mount an assembly is at a premium. provision of a compact, modular filter assembly would be an improvement over conventional filter assemblies in which the filter elements are not arranged or configured to minimize the volume or space envelope of the filter element housing.
Another object of the present invention is to increase the filtering capacity of a filter cartridge of constant size by connecting a manifold cap to a filter cartridge housing and by supporting the filter cartridge within its housing without projecting any foreign support members or the like through the body of the filter cartridge.
Contaminant build-up on interior surfaces of filter housings and inside drains used to discharge collected material from filter housings is a problem known to disturb the operation of some conventional filter assemblies. In such cases, it is necessary to disassemble the filter assembly periodically so that it can be cleaned thoroughly. For example, in the cleaning apparatus disclosed in U.S. Pat. No. 3,353,339 to Walter, the interior walls of the filter housing and the drain assembly are exposed to an untreated compressed air stream. Unwanted build-up of contaminant material can occur in that cleaning apparatus because the compressed air stream is allowed to communicate directly with surfaces and components in interior regions of the filter housing before the compressed air stream is introduced into the filter element itself. Development of an improved modular filter assembly in which the filter element communicates directly with the inlet and outlet manifold would advantageously reduce unwanted contaminant build-up inside the filter assembly.
Yet another object of the present invention is to provide a manifold for capping a cartridge housing and a compact filter cartridge positionable in the housing to mate with the manifold cap so that a compressed air stream conducted through the manifold cap toward a point of use is decontaminated in the filter cartridge without allowing the compressed air stream discharged from the manifold cap to contaminate the housing or its liquid drain.
According to the present invention, an apparatus is provided for cleaning a compressed air stream conducted through an air line. The apparatus includes a cartridge housing formed to include an interior region and a cartridge-receiving opening communicating with the interior region. A filter cartridge is disposed in the interior region of the cartridge housing. The filter cartridge includes means for filtering a compressed air stream to remove at least one selected contaminant therefrom.
A manifold is formed to include means interconnecting the air line and the filter cartridge for conducting the compressed air stream in the air line between the air line and the filter cartridge. Means is provided for selectively connecting the manifold to the cartridge housing to cover the cartridge-receiving opening and to place the manifold adjacent to the filter cartridge so that the conducting means is coupled to the filtering means. The entire connecting means is situated to lie in spaced-apart relation to the filter cartridge so that the connecting means extends about the filter cartridge upon connection of the manifold to the cartridge housing to maximize the interior filter-containing region of the cartridge housing.
In preferred embodiments, the filtering means includes a pair of coaxially aligned filter elements. A first of the filter elements is formed to include a central aperture extending in an axial direction therethrough. A second of the filter elements is situated in the central aperture of the first filter element.
The apparatus further includes means for retaining the filter cartridge in a predetermined position in the interior region of the cartridge housing adjacent to the manifold and in spaced-apart relation to the connecting means. In this predetermined position, the filtering means of the filter cartridge is in fluid communication with the conducting means of the manifold to permit a compressed air stream diverted from the air line to be cleaned in the filter cartridge without contaminating interior regions or drains of the apparatus. The retaining means is configured to permit removal of the filter cartridge from the interior region of the cartridge housing through the cartridge-receiving opening upon disconnecting the manifold from the cartridge housing.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.